This may come as a surprise, but the term “ideal weight” was discarded years ago and replaced with "desirable weight." This makes more sense. Sometimes there's a big gap between what's ideal and what's attainable.
Nevertheless, this new terminology poses practical difficulties. Why does one person look heavier even if they are the same age, gender, height, and weight as another? 
Several factors explain these differences: bone structure, muscle mass, and perception. Each person has as a mental image of the body that he or she desires.
When you’re trying to lose weight, changes in your weight should serve only to let you know that you're on the right track. It's preferable and recommended that you monitor your progress based on changes to your figure. You've reached your goal when you're able to say: "This is the body I want!” regardless of how much you weigh at the time.
Your best allies in this process are your full-length mirror and the changes in your clothing size.
